Adjustable mechanical sighting mechanism for firearms

ABSTRACT

An adjustable mechanical sighing mechanism for firearms has a sight blade mount defining an internal passage having first and second outwardly flaring passage end surfaces. An adjustment screw having an external tapered surface is in engagement with the first of the outwardly flaring passage end surfaces. A sight blade structure defines a sight adjustment member having an internally threaded screw passage that receives the adjustment screw. A lock nut is threaded onto the adjustment screw and has an external tapered surface in engagement with the second outwardly flaring passage end surface. The sight blade mount defines a slot through which a support for the sight adjustment member is movable, providing for windage adjustment of the sight blade structure by rotation of the adjustment screw. The tapered surfaces of the adjustment screw and lock nut provide for locking of the sight blade at any desired position.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates generally to sighting mechanisms for firearms and more particularly concerns an adjustable mechanical sighting mechanism for handguns and other firearms. Even more particularly the present invention concerns a mechanical sighting mechanism having a sighting blade member that is adjustable for elevation and windage to control the strike point of a bullet fired by the firearm and is provided with a novel adjustment and locking mechanism to ensure against inadvertent movement of the sight blade member even when the firearm is subjected to the impacts and jarring of prolonged firing, such as during a shooting match or during tactical shooting and firearm handling activities.

Description of the Prior Art

Though it is to be understood that the mechanical sighting mechanism of the present invention is applicable for use with a number of different types of firearms, for purposes of simplicity, to facilitate a ready understanding of the spirit and scope of the present invention. However, for purposes of simplicity the mechanical sighting mechanism is discussed particularly as to its application for handguns, particularly the 1911 A1 semi-automatic pistol and handguns of similar nature and any handgun having a rear sight mechanism that is adjustable for elevation and windage.

An adjustable pistol sight mechanism has been manufactured and sold for many years by BoMar. The BoMar rear sight mechanism has both elevation and windage adjustment capability which have the conventional form of adjustment screws. The rear blade of the sight mechanism is positioned by the adjustment screws, but cannot be locked against inadvertent movement. The heads of the adjustment screws have circular edges defining closely spaced notches that are engaged by pin members to provide for incremental adjustment of the position, elevation and windage, of the sighting mechanism.

SUMMARY OF THE INVENTION

It is a principal feature of the present invention to provide a novel adjustable mechanical rear sight mechanism for handguns and other firearms having the capability for being selectively adjusted for windage and elevation;

It is another feature of the present invention to provide a novel adjustable mechanical sighting mechanism having a laterally moveable sight blade adjustment and locking mechanism that has the capability for being moved to any selected position of windage adjustment and locked against inadvertent movement, such as by vibration, shock forces or impacts;

Briefly, the various objects and features of the present invention are realized through the provision of an adjustable mechanical rear sight mechanism having a sight mount base defining a dive-tail projection enabling the base to be mounted to a corresponding dove-tail slot of the firearm. In the case of a 1911 A1 type of firearm, the dove-tail slot is defined in the reciprocating slide member.

A pivotally moveable top plate member is mounted to the sight mount base by a hinge pin and defines a sight blade mount having a laterally oriented internal passage that is defined in part by oppositely tapered outwardly flared internal surfaces. The sight blade mount defines an elongate slot that receives a central support structure of a sight blade member and defines a tubular receptacle within which is received a tubular internally threaded sight adjustment member that is an integral component of the one-piece sight blade member.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the preferred embodiment thereof which is illustrated in the appended drawings, which drawings are incorporated as a part hereof.

It is to be noted however, that the appended drawings illustrate only a typical embodiment of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.

In the Drawings:

FIG. 1 is an isometric illustration of a firearm sighting mechanism that is constructed according to the principles of the present invention and represents the preferred embodiment;

FIG. 2 is a side elevational view of the firearm sighting mechanism of FIG. 1;

FIG. 3 is a plan view of the firearm sighting mechanism of FIGS. 1 and 2;

FIG. 4 is a sectional view taken along the line 4-4 of FIG. 2;

FIG. 5 is an exploded isometric illustration showing the various components of the firearm sighting mechanism of FIGS. 1-4;

FIG. 5 a is a fragmentary sectional view of the mounting base and pivotally movable top plate of the sighting mechanism; and

FIG. 5 b is a side elevational view of the front sight blade member showing the tubular internally threaded sight adjustment member thereof.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

Referring now to the drawings and first to FIG. 1, an adjustable sighting mechanism constructed according to the principles of the present invention is shown generally at 10. The adjustable sighting mechanism 10 incorporates a sight mounting base 12 having a depending dove-tail projection 14 defining undercut angulated dove-tail surfaces 16 and 18. The dove-tail projection 14 is adapted to be received within a sight mounting slot of a firearm component having a corresponding dove-tail configuration (not shown). As an example, the reciprocating slide of the well known 1911-A1 handgun defines a dove-tail sight mounting slot within which the dove-tail mounting projection of a mechanical sighting device is received in tight fitting relation. Sight mounting crews extend through the reciprocating slide structure and are threaded into the dove-tail mounting projection to secure the sight base in immovable relation with respect to the reciprocating firearm slide. Though the adjustable firearm sighting mechanism of the present invention is particularly adapted for use as a handgun sighting device, it is to be understood that it is well adapted for use on shoulder fired arms, such as rifles, shotguns, machine guns and the like without departing from the spirit and scope of the present invention.

The upper portion of the sight mounting base 12 is machined or otherwise formed to define a pair of spaced, upwardly projecting elongate parallel bosses 20 and 22 with a slot 24 defined therebetween. The slot 24 is defined by spaced parallel edge surfaces 26 and 28 of the pair of spaced, upwardly projecting elongate parallel bosses 20 and 22. The slot 24 between the bosses 20 and 22 is defined in part by a relatively thin bottom wall 30 which is an integral part of the sight mounting base 12. Internally threaded set screw holes 32 and 34 extend through the sight mounting base 12 at the elongate parallel bosses 20 and 22 and receive set screws 36 and 38 which engage an internal surface of the dove-tail slot of the firearm to secure the mounting base immovably within the dove-tail slot.

A pivotally moveable top plate member 40 is pivotally mounted to the sight mounting base 12 and provides the sighting mechanism with the capability for elevation adjustment. At its rear end portion the top plate member 40 defines a hinge pin bore 42 within which the central portion of a hinge pin 44 is movably received. The elongate parallel bosses 20 and 22 define aligned hinge pin bores 46 and 48 within which are received respective end portions of the hinge pin 44. One of the hinge pin openings 46 or 48 may be internally threaded and thus adapted to receive an externally threaded portion 50 of the hinge pin. Alternatively, the hinge pin may be frictionally retained within one or both of the hinge pin openings 46 or 48 or may be secured in immovable relation with the mounting base in any other suitable manner.

It is desirable to provide the moveable top plate member 40 with resistance to upwardly directed pivotal movement and to provide the moveable top plate member 40 with a force tending to move it pivotally upwardly and to prevent it from inadvertently moving downwardly. This feature is accomplished by providing the bottom wall 30 of the mounting base with an upwardly facing spring recess 52 within which is received the lower end of one or more compression springs 54. The upper end of the compression spring or springs is received within a corresponding downwardly facing spring recess 56 of the pivotally moveable top plate member 40. The compression spring or springs 54 continuously urge the top plate 40 pivotally upwardly about the hinge pin 44, tending to raise the sighting mechanism for elevation. The force of the compression spring or springs 54 is overcome by the downwardly directed force of an elevation adjustment member 58, such as an adjustment screw, that is moveable within an adjustment member receptacle 60 of the top plate 40 and is rotatably adjustable to permit controlled upward and downward movement of the top plate.

The top plate member 40 is provided with a front sight blade 62 having spaced upwardly extending projections 64 and 66 defining a sighting slot 68 therebetween. The front sight blade defines a generally planar surface 67 facing the eye of the user of the firearm. The surface 67 is roughened by the presence of closely spaced knurling ridges and grooves 69 or any other roughened or non-reflective surface to minimize the potential for any light or image reflection being directed to the eye of the user. Also, when the sighting mechanism is in assembly with the dove-tail mounting slot of a firearm, the planar surface 67 will typically be disposed slightly inclined from the vertical, with its spaced upwardly extending projections 64 and 66 slightly closer to the user as compared with the position of the lower edge portion of the planar surface. This feature also minimizes the potential for the reflection of light toward the eye of the user. If desired, however, the planar surface 67 may be vertically oriented or oriented with its upper portion further away from the user than its lower edge portion. Side edge portions of the spaced upwardly extending projections 64 and 66 are cut away, so as to define concavely curved or inclined side edge surfaces 71 and 73 to minimize the potential for the sight blade catching on clothing or adjacent objects as the firearm is handled.

It is appropriate to mount the front sight blade so that it is movable upwardly and downwardly along with the pivotally moveable top plate member 40 for sighting elevation and is moveable laterally for windage adjustment. It is also desirable to provide the facility for positively locking or securing the front sight blade at any desired laterally adjusted position so that the front sight blade will remain in position even during the impact and vibration forces that occur as the firearm is subjected to repeated and prolonged firing activities. This feature is accomplished by providing at the forward end of the pivotally moveable top plate member 40 a laterally extending sight blade mount 70 having a width that may essentially correspond with the width of the sight mounting base 12 as defined by the exterior surfaces 72 and 74 thereof. The laterally extending sight blade mount 70 is machined to define a laterally oriented passage 76 having oppositely tapered outwardly flaring passage end surfaces 78 and 80 and has spaced elongate nose surfaces 82 and 84 having elongate rounded nose edges 86 and 88 and defining an elongate slot 90.

The front sight blade member 62, shown in the exploded isometric illustration of FIG. 5 and also shown in the side elevational view of FIG. 5 b and other FIGS., defines a nose receiving profile having a central support structure 92 and concave curved surfaces 94 and 96 corresponding to the configurations of the spaced elongate nose surfaces 82 and 84. From the front sight blade member 62 extends a tubular sight adjustment member 98 which is fixed to the central support structure 92 and has a length less than the width of the front sight blade structure. The tubular sight adjustment member 98 defines an internally threaded section 100 having threaded engagement with an externally threaded section of an adjustment and lock screw 102 having a tapered screw head 104 and having a threaded screw shaft 103.

The tapered screw head 104 defines a frusto-conical external surface 106 having a greater angle of taper as compared with the tapered internal outwardly flaring surface 78 so that contact between the tapered surfaces 78 and 106 occurs at the outward extent of the tapered internal surface 78 as is evident from FIG. 4. The outer extent of the adjustment and lock screw 102 is defined by a circular portion of the tapered screw head 104 which defines evenly spaced windage adjustment slots 105. Within the laterally oriented passage 76 the laterally extending sight blade mount 70 defines an elongate longitudinal slot 107, within which is located a small diameter windage adjustment control element 107, which is shown in the side elevational view of FIG. 2. The small diameter windage adjustment control element 107 is positioned to engage within the evenly spaced windage adjustment slots 105, thus providing the adjustment and lock screw 102 with increments of adjustment. This feature is typically known as “clicks” of adjustment, with each click or increment of windage adjustment to change the strike of a bullet by a selected distance. For example, one click of adjustment for shooting a known distance may change the strike of the bullet one inch left or right, for example, depending on the direction of rotation of the adjustment and lock screw.

A lock nut 108 having an internally threaded opening 110 is disposed in threaded assembly with an end 112 of the threaded shaft of the lock screw 102. The lock nut 98 defines an externally tapered or frusto-conical surface 114 having a greater angle of taper as compared with the angle of taper of the tapered outwardly flaring passage end surface 80. As the lock nut 108 is threaded onto the shaft of the adjustment and lock screw 102, such as by means of a blade type screw-driver engaging with a blade slot 116 of the lock screw, contact between the tapered surfaces 80 and 114 will occur at the outer extent of the tapered frusto-conical surface 114. This feature minimizes any potential for incursion of dirt, excess oil, water or any other debris into the laterally oriented passage 76 of the laterally extending sight blade mount 70. Rotation of the adjustment and lock screw 102 is achieved by means of a simple Allen wrench that engages within a wrench drive receptacle 118 of the screw head 104.

As mentioned above, the laterally extending sight blade mount 70 defines an elongate slot 90. This feature provides the essentially tubular blade mount structure with a degree of flexibility though it is of rather rigid construction. As the tapered surfaces 106 and 114 are drawn toward one another by rotating and tightening of the lock nut 108 on the shaft of the adjustment and locking screw these tapered surfaces will have forcible reaction with the internally tapered outwardly flaring passage end surfaces 78 and 80 within the lateral passage 76 of the laterally extending sight blade mount 70. This forcible activity enhances the frictional resistance between the respective tapered surfaces, thus minimizing the potential for rotational movement of either the adjustment screw or the lock nut from an adjusted position. The forcible activity also tends to flex and expand the spacing of the elongate nose surfaces 82 and 84, enhancing the resistance of the adjustment screw and lock nut from inadvertent rotation even when the sighing mechanism is subjected to the repeated impacts and jarring of prolonged rapid fire of the firearm. Also, forcing the tapered surfaces of the adjustment screw and lock nut against the respective internal tapered surfaces 78 and 80 causes the adjustment screw 102 to be subjected to tension so that the threads of the adjustment screw and lock nut will be maintained in positive engagement even during component expansion or contraction due to significant temperature changes, ensuring against any undesired movement of the adjustment mechanism within the laterally extending sight blade mount 70.

The sight mounting base 12 is installed to the dove-tail slot or receptacle of the firearm by inserting the depending dove-tail projection 14 into the dove-tail slot and extending an Allen wrench through the internally threaded set screw holes 32 and 34 of the sight mounting base 12 and actuating set screws to apply downward set screw force to the bottom surface of the dove-tail slot, thus driving the inclined surfaces 16 and 18 of the dove-tail projection 14 upwardly for retaining frictional engagement to maintain the mount 12 against movement relative to the firearm. When the sight mounting base 12 is installed, the pivotally moveable top plate member 40 may be mounted to the sight mounting base by the hinge pin 44 or may be mounted to the sight mounting base at a later time. At the time the top plate member is mounted, the compression spring or springs 54 will be positioned with the ends there disposed within the respective spring recesses 52 and 56. The top plate member will then be manipulated so that the top plate member will pivot into the slot 24 of the sight mounting base 12 and the elevation adjustment screw member 58 will be rotated sufficiently to engage within a screw hole of the reciprocating slide or other component of the firearm and retain the top plate member against free rotation about the hinge pin 44.

When the top plate member 40 is installed the front sight blade member 62 may already be in place, with the central support structure 92 disposed within the elongate slot 90 of the laterally extending sight blade mount 70 and the tubular internally threaded sight adjustment member 98 located within the laterally oriented passage 76. For its installation, the front sight blade member 62 is moved laterally for insertion of the central support structure 92 into the elongate slot 90, thus positioning the tubular internally threaded sight adjustment member 98 within the tubular or cylindrical receptacle section that is defined by the laterally oriented passage 76. The adjustment and lock screw 102 is threaded into the internally threaded section 100 of the tubular internally threaded sight adjustment member 98. Rotation of the adjustment and lock screw 102 causes lateral movement of the sight blade structure relative to the laterally extending sight blade mount 70. This relative movement is accomplished by rotation of the threaded section of the adjustment and lock screw 102 within the internally threaded section 100 of the tubular internally threaded sight adjustment member 98. Axial movement of the adjustment and lock screw 102 is limited by engagement of the frusto-conical external surface 106 with the tapered outwardly flaring passage end surface 78. At this point the lock nut 108 is threaded onto the threaded end of the adjustment and lock screw 102 and is tightened onto the screw by rotating the lock nut with a blade type screw driver. Simultaneously, the adjustment and lock screw 102 is prevented from rotation or intentionally rotated by rotating the screw 102 with a simple Allen wrench which engages within the wrench drive receptacle 118. By controllably rotating the adjustment and lock screw 102 and the lock nut 108 the sight blade member 62 is moved laterally to its desired position relative to the laterally extending sight blade mount 70 and is locked in place by tightening the lock nut on the screw 102.

Though the laterally extending sight blade mount 70 is rather rigidly constructed to ensure the durability and operative character of the adjustable sighing mechanism, the presence of the elongate slot 90 through which the central support structure 92 is movable provides the sight blade mount 70 with a degree of flexibility. When the lock nut is tightened onto the adjustment and lock screw 102 the surfaces 106 and 114 will react with the tapered outwardly flaring passage end surfaces 78 and 80, thus subjecting the spaced elongate nose surfaces 82 and 84 to expansion forces. These forces also cause the outer extremities of the differently tapered surfaces 106 and 114 to establish tight engagement at the outer portions of the tapered outwardly flaring passage end surfaces 78 and 80, providing metal to metal seals that minimizes the potential for dust, oil, water and other debris entering the laterally oriented passage 76. The metal to metal seals further enhance the retention of lubricating oil within the passage 76 and on the mechanical components that are present within the passage. This sealing feature ensures the resistance of the mechanical sighting mechanism to unusual wear or damage even when the firearm is utilized in rather hazardous conditions.

Since firearms are often subjected to wide temperature fluctuation during use, it is possible that the mechanical components of a sight mechanism can change to the point that expansion or contraction of sight components can result in inadvertent movement of the sight mechanism, resulting in conditions of firearm inaccuracy. The forces of tightening the lock nut 108 on the threaded shaft of the adjustment and lock screw 102 subject the screw 102 to tensile forces, tending to stretch and elongate the screw. With the screw maintained under tension, expansion or contraction of sight components by changes in temperature will simply result in changes in the amount of tensile forces on the screw 102 and will not cause other components to be tightened or loosened to the extent that the sighting mechanism might lose its condition of precision aiming.

In view of the foregoing it is evident that the present invention is one well adapted to attain all of the objects and features hereinabove set forth, together with other objects and features which are inherent in the apparatus disclosed herein.

As will be readily apparent to those skilled in the art, the present invention may easily be produced in other specific forms without departing from its spirit or essential characteristics. The present embodiment is, therefore, to be considered as merely illustrative and not restrictive, the scope of the invention being indicated by the claims rather than the foregoing description, and all changes which come within the meaning and range of equivalence of the claims are therefore intended to be embraced therein. 

1. An adjustable mechanical sighting mechanism for firearms, comprising: a sight blade mount defining an internal passage having first and second outwardly flaring passage end surfaces; an adjustment screw having an external tapered surface disposed in engagement with said first of said outwardly flaring passage end surfaces; a sight blade member defining an internally threaded screw passage being received in operative blade moving engagement with said adjustment screw; and a lock nut being threaded to said adjustment screw and having an external tapered surface disposed in engagement with said second of said outwardly flaring passage end surfaces.
 2. The adjustable mechanical sighting mechanism of claim 1, comprising: tightening of said lock nut onto said adjustment screw causing increase of engagement force of said external tapered surfaces of said adjustment screw and said lock nut with said first and second outwardly flaring passage end surfaces.
 3. The adjustable mechanical sighting mechanism of claim 1, comprising: tightening of said lock nut onto said adjustment screw causing application of tensile forces to said adjustment screw.
 4. The adjustable mechanical sighting mechanism of claim 1, comprising: said sight blade mount defining an elongate slot having communication with said internal passage; a support member being defined by said sight blade structure and being movable within said elongate slot; and an adjustment member being supported within said internal passage by said support member and being moved to selected positions within said internal passage by said adjustment screw.
 5. The adjustable mechanical sighting mechanism of claim 4, comprising: said elongate slot defining spaced elongate nose sections on said sight blade mount; and said adjustment member defining an internally threaded screw passage receiving said adjustment screw therein and being moved within said internal passage upon rotational movement of said adjustment screw.
 6. The adjustable mechanical sighting mechanism of claim 5, comprising: forcible reaction of said tapered surfaces of said adjustment screw and lock nut with said first and second outwardly flaring passage end surfaces upon tightening rotation of said lock nut causing friction induced locking of said sight blade member against inadvertent movement thereof from any adjusted position relative to said sight blade mount.
 7. The adjustable mechanical sighting mechanism of claim 5, comprising: said spaced elongate nose sections being flexible; and said forcible reaction of said tapered surfaces of said adjustment screw and lock nut with said first and second outwardly flaring passage end surfaces causing flexing of said spaced elongate nose sections and subjecting said adjustment screw to tensile forces.
 8. The adjustable mechanical sighting mechanism of claim 5, comprising: a sight mount base having a dove-tail mount projection for mounting engagement within a dove-tail mounting slot of a firearm; said sight blade mount being pivotally mounted to said sight mount base; and at least one spring member being interposed between said sight mount base and said sight blade mount and urging said sight blade mount in one pivotal direction; and a retainer and elevation adjustment screw securing said sight blade mount and being rotatably adjusted for overcoming the force of said spring member and establishing a selective adjusted elevation position of said sight blade mount and said sight blade member.
 9. An adjustable mechanical sighting mechanism for firearms, comprising: a sight blade mount defining an internal passage and defining an elongate slot in communication with said internal passage, said sight blade mount defining locking surfaces; a sight blade member defining a sighting slot and having a support moveable within said elongate slot and having an adjustment member movable within said internal passage by said support and defining an internally threaded adjustment screw passage; an adjustment screw having an external tapered surface disposed in engagement with said first outwardly flaring passage end surface and being threaded within said internally threaded adjustment screw passage, selective rotation of said adjustment screw moving said adjustment member within said internal passage, moving said support within said elongate slot and moving said sight blade member with respect to said sight blade mount; a lock nut being threaded to said adjustment screw; and said adjustment screw and said lock nut being disposed for locking engagement with said locking surfaces upon tightening of said lock nut on said adjustment screw.
 10. The adjustable mechanical sighting mechanism of claim 9, comprising: said internal passage being defined in part by first and second outwardly flaring passage end surfaces; said adjustment screw defining a tapered external surface disposed for engagement with said first outwardly flaring passage end surface; said lock nut defining a tapered external surface disposed for, engagement with said second outwardly flaring passage end surface; and tightening of said lock nut on said adjustment screw developing forcible engagement of said tapered external surfaces of said adjustment screw and said lock nut with said first and second outwardly flaring passage end surfaces and locking said sight blade member against inadvertent movement.
 11. The adjustable mechanical sighting mechanism of claim 9, comprising: said spaced elongate nose sections being flexible; and forcible reaction of said tapered surfaces of said adjustment screw and lock nut with said first and second outwardly flaring passage end surfaces responsive to tightening of said lock nut causing flexing of said spaced elongate nose sections and subjecting said-adjustment screw to tensile forces.
 12. The adjustable mechanical sighting mechanism of claim 8, comprising: said tapered external surfaces of said adjustment screw and lock nut having different angles of taper as compared with the angles of taper of said first and second outwardly flaring passage end surfaces resulting in contact of outer edges of said tapered external surfaces of said adjustment screw and lock nut with said first and second outwardly flaring passage end surfaces providing metal to metal engagement therebetween at said outer edges.
 13. The adjustable mechanical sighting mechanism of claim 8, comprising: a sight mount base having a dove-tail mount projection for mounting engagement within a dove-tail mounting slot of a firearm; said sight blade mount being pivotally mounted to said sight mount base; and at least one spring member being interposed between said sight mount base and said sight blade mount and urging said sight blade mount in one pivotal direction; and a retainer and elevation adjustment screw securing said sight blade mount and being rotatably adjusted for overcoming the force of said spring member and establishing a selective adjusted elevation position of said sight blade mount and said sight blade member. 